ROLLER-CUTTER DRILLING BIT Russian patent published in 2002 - IPC

FIELD: drilling tools, particularly, roller-cutter drilling bits designed for drilling holes in open casts. SUBSTANCE: roller-cutter drilling bit has a body with hollow shank to which legs with air courses, bearing flushing courses are secured, roller-cutters installed on leg cone pins, unit if forced air and water flushing and bearing lubrication in the form of bushing secured to shank and communicated with shank hollow, circular chamber formed by bushing internal surface and nozzle located inside bushing held by spring resting with its one end on bottom of shank cavity, and with its other end, on four-leg washer connected with nozzle having side windows which are covered by bushing in idle position of drilling bit. Bushing circular chamber is opened into shank cavity and provided with side windows for supply of working agent. Nozzle is covered from atop by cover. EFFECT: simplified design of roller-cutter drilling bit and its higher operating reliability. 1 dwg